Update on Johne’s Disease Testing in BC Dairy Herds

Growing Forward is the federal-provincial partnership that funded a project to test BC cattle that were over 18 months of age for Johne’s disease. This article reports the results from the 4,565 dairy animals from 30 herds that were tested for Johne’s disease in 2011 and 2012. The results from 2 herds that each submitted fewer than 10 samples are not included in this analysis.

The table below provides more information on the 30 herds broken down by region. A herd is considered positive if at least one animal tested positive.

Region # of Animals Tested #of Herds Tested

# of Herds Testing Johne’s Positive

Average # of Samples per Herd
Thompson Okanaga 1,523 10 1 152
Fraser Valley 1,453 9 3 161
Vancouver Island 1,589 11 0 144

Caution is required in comparing the Johne’s disease levels between the regions because the number of herds in each is small, and the herds and animals were not randomly sampled.

Among the 4 dairy herds that tested positive for Johne’s disease, the percentage of animals that tested positive was low — typically, less than 2%. However, Johne’s testing is expected to underestimate both the number of herds positive and the number of animals positive within a herd.

For more information on this project’s results please contact:

Brian Radke at the

BC Ministry of Agriculture

Email: brian.radke@gov.bc.ca

Phone: 604.556.3066.

About BC Dairy

BC Dairy is a not-for-profit organization representing BC’s dairy farmers.